Sustained release lingual thioctic acid delivery systems

ABSTRACT

The invention provides new methods of administering alpha-lipoic acid to patients. A diffusion rate limiting matrix is utilized to buccally, lingually and/or sublingually deliver the alpha-lipoic acid. This sustained release matrix is intended for general nutritional supplementation and/or the treatment of various physiological disorders, such as diabetic neuropathy. Due to its lingual nature, this rate limiting matrix can deliver approximately IV-equivalent plasma levels of thioctic acid and is not meant to be swallowed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is a continuation of U.S. patent application Ser. No.16/102,711, filed Aug. 13, 2018, which is a continuation of U.S. patentapplication Ser. No. 15/050,462, filed Feb. 22, 2016, which is acontinuation-in-part of U.S. patent application Ser. No. 13/602,093,filed Aug. 31, 2012 (now U.S. Pat. No. 9,265,753), and claims thebenefit of U.S. Provisional Patent Application No. 61/575,900, filedAug. 31, 2011. This application incorporates the content of all of theseprevious patent applications by reference and claims the benefit ofpriority of each one of these patent applications.

FIELD OF THE INVENTION

The present invention relates to tablets comprising limited releaselingual/sublingual delivery systems for thioctic acid (alpha-lipoicacid) and the use of such tablets for the promotion of health and thetreatment of conditions, such as diabetic neuropathy.

BACKGROUND OF THE INVENTION

Thioctic acid is also known as lipoic acid, alpha lipoic (sometimeswritten alpha-lipoic) acid, or ALA. Thioctic acid has two chiralenantiomers. It is found as R-(+)-lipoic acid (RLA) and S-(−)-lipoicacid (SLA), and a racemic mixture of the two R/S-Lipoic acids.Additionally, each of these thioctic acid enantiomers exist in reduced(dihydro-lipoic acid) and oxidized forms. The limited releaselingual/sublingual delivery system of this disclosure is effective forany and all of the above thioctic acid variants. The term thioctic acid,alpha lipoic acid, or ALA refers to all of these various species oflipoic acid, unless specifically referred to otherwise.

The term of thioctic acid is more common in Europe. Alpha lipoic acid orALA is more common in the United States. The scientific literature usesall these terms and therefore we will use thioctic acid, alpha lipoicacid, and/or ALA interchangeably.

Lingual/Sublingual (Oral Mucosal Transmission)

We clarify our use of “lingual” or “lingual/sublingual” as follows.Typically, lingual refers to the tongue while sublingual refers to thetissues below the tongue and the underside of the tongue. Buccalgenerally refer to the cheeks. Oral refers to the entire mouth; however,it can also mean a pill, or the like, that is swallowed rather thandissolved in the mouth. Conversely, we believe most people understand“lingual” or “lingual/sublingual” to be something that is dissolvedorally rather than swallowed intact. Another way to say this is, the ALAis transferred from the oral cavity to the body's blood stream bybuccal, lingual, and sublingual absorption; or the ALA is buccally,lingually and sublingually delivered. Therefore, unless specifiedotherwise, we use of the terms “lingual” or “lingual/sublingual” or“buccal/lingual/sublingual” to refer to a formulation dissolving in anypart(s) of the entire mouth and that the active or key ingredient(s),i.e., ALA, enters the general bloodstream through various or multipleoral tissues rather than being limited to any particular portion ortissue of the mouth. We intend the following terms to have the samemeaning as “lingual” or “lingual/sublingual” or“buccal/lingual/sublingual”: lingual absorption, lingually delivered;Oral Mucosal Delivery, Oral Mucosal Transmission, Oral MucosalAdministration; Oral Epithelial Delivery, Transmission orAdministration; and Oral Dissolution & Transmission (Oral D&T).

Description of the Related Art

Thioctic acid is believed to be beneficial in several applications, suchas preventing organ dysfunction, the treatment of various neuropathiesand polyneuropathies, and use as an antioxidant. Thioctic acid has beenprimarily administered by two methods in the prior art.

High Absorption Rate and High Plasma Levels/Blood Stream

First, it has been administered via intravenous (IV) therapy. In IVtherapy, a solution containing thioctic acid is delivered through an IVneedle directly to a patient's blood stream. This method shows thebenefits of a high absorption rate and high plasma levels.

IV therapy becomes problematic, however, when the therapy is designedfor use in the long-term care of a patient. In order to utilize IVtherapy as a delivery system, the IV must be administered by a medicalprofessional. This typically requires the patient to visit a healthcareprovider's office or hospital each time the thioctic acid is to beadministered. The time required to visit the office frequentlydiscourages the patient from continuing these visits. Thus, the patientwill often discontinue treatment due to the inconvenience of makingtrips to the provider's office. The necessity for treatment through anoffice or hospital also creates a high cost for patients, insurancecompanies, and researchers who want to perform clinical trials.Furthermore, in the event that the patient continues treatment, frequentIV use may cause vein collapse and oxidative stress in the patient.

The second method typically utilizes an orally administered, GI deliverysystem using a tablet, powder, or soft-gel formulation of thioctic acid.This offers a method of administration which does not require a healthcare provider's oversight. However, tablets and powders of thioctic acidare difficult for the human body to absorb.

Refined thioctic acid is insoluble in water at normal pH and at the acidpH seen in the stomach, although it is soluble in fat solvents. Thedl-form of thioctic acid is likewise insoluble in water and soluble infat solvents, but it can form a water-soluble sodium salt that isaqueous in water solutions that exist at a pH of about 7.4. However,this sodium salt also has a poor solubility at acid pH.

Due to this solubilization problem, thioctic acid taken in tablet andpowder forms is almost entirely dependent upon bile salts in the smallintestine for dispersal, which results in a slow absorption rate and lowsystemic plasma levels. Once bile salt dispersal of thioctic acidcrystals has occurred, thioctic acid can penetrate epithelium in themanner of fat-soluble drugs, as well as utilize absorption mechanisms inthe small intestine specific to medium chain fatty acids. Soft-gelvariations of solubilized thioctic acid, and oral liquid solutions, havebeen developed to speed up the dispersal process. However, for the mostpart these solutions are prone to polymerization and degradationreactions and are unstable during long term storage. More significantly,all previous oral delivery systems (including soft-gels and oralsolutions) utilize the stomach and gastrointestinal (GI) tract forabsorption.

Since the liver is the major organ implicated in the removal of thiocticacid from plasma, with a removal rate nearly equal to that of theclearance of plasma through the liver, slow GI absorption rates resultin low systemic plasma levels due to the necessary passage of ingestedsubstances through the hepatic portal vein of the liver (the first passmechanism).

To clarify, by GI absorption we mean the absorption of ALA by the GItract, then ALA's transmission to the bloodstream via the hepatic portalvein, and then finally the ALA's entering of the body's generalbloodstream where ALA can be subsequently measured in the systemic bloodplasma. In contrast, the absorption directly, and only, by the GI tracttissues without further transmission to the bloodstream will be referredto as GI Assimilation.

Due to the insoluble nature of thioctic acid and/or the liver's functionto remove it from both systemically circulating plasma and the firstpass mechanism of the hepatic portal vein, oral delivery systems thatutilize the stomach and small intestine for absorption necessarilyequate to relatively low absorption profiles, such that only a smallpercent of a given dose actually becomes utilized by the body.Therefore, a large degree of waste occurs when GI absorption mechanismsare utilized, and thus maximal benefits from thioctic acidsupplementation are not achieved through GI absorption mechanisms.

Previous attempts to overcome the low absorption profiles of oralthioctic acid doses have produced their own problems and side-effects.When high concentrations of thioctic acid make continued contact withcells in the mouth and GI tract (including the stomach), those cells mayswell and burst, causing an apoptotic “burn” effect. This apoptoticeffect is what caused lethality in animals utilized for LD50 studies,where said animals died from liver failure. Upon histologicalexamination, liver mitochondria of said animals were seen to have burstdue to an osmotic imbalance as thioctic acid flooded into these cells.As such, due to this osmotic/apoptotic effect, current formulations of aswallowed tablet, powder, or soft gel can be uncomfortable or harmful tothe patient, particularly when taken in high enough doses to produce IVequivalent plasma levels.

An alternative solution is needed to address one or more of theseshortcomings in the prior art.

SUMMARY OF THE INVENTION

A limited release lingual/sublingual delivery system for thioctic acidis provided.

A diffusion-limiting binding agent, either hard or soft, in thelingual/sublingual formulations may include, but is not limited to:sucrose, isomalt, dextrose, lactitol, sorbitol, maltose and chicle.

The limited-release lingual/sublingual delivery system may be a lozenge,caramel, gum, or other release-limiting matrix formulation placed in thepatient's mouth that that is intended to remain in the mouth. That is,the patient is not encouraged to swallow the delivery system. Theformulation contains a concentration of thioctic acid between 1% and 25%by mass, preferably at a concentration of approximately 2% by mass.

Individual lozenges, candies, or other lingual delivery systems areexpected to be from 1.0 g to 30.0 g, with thioctic acid dose variationsfrom 10 mg to 600 mg. However, extremely low-dose variations (from 5.0mg to 10 mg) of thioctic acid are anticipated, such that lozenges forgeneral consumption as a supplement are also included, in addition tothe high-dose formulations intended for specific therapeutic effects.These therapeutic applications may include the treatment of Alzheimer's,Diabetic peripheral neuropathies, retinal neuropathies, and otherphysiological states where thioctic acid therapy is advised or underinvestigation.

DETAILED DESCRIPTION OF THE INVENTION

Through the course of study, while inventing the first marketed form ofsolubilized thioctic acid (ThioGel™), the inventor of thislimited-release lingual/sublingual delivery system noted thatsolubilized forms of thioctic acid, be they in aqueous solutions or infat solvents, are able to pass through the epithelium of the mouth andGI tract due to the dispersed nature of the molecules. However, initialattempts to utilize lingual absorption mechanisms resulted in a burneffect that was revealed to be equivalent to the apoptotic effectobserved in the livers of animals utilized for LD50 studies.

To be clear, not every substance can pass through the epithelium of themouth (oral epithelium). It is well known that a substance can beadministered lingually, i.e., dissolved in the mouth, but that does notmean that the substance will pass through the oral epithelium and intothe bloodstream. Therefore, some substances, nutraceuticals, or drugscan be effectively administered lingually, and some cannot. In the caseof ALA, it was not obvious or expected that it could be administeredlingually, i.e., pass through the oral epithelium. That ALA could bedelivered through the oral epithelium was the first discovery made bythe primary inventor.

As noted in a later paragraph: “Not all lingual/sublingual deliverysystems are effective. Instead, the act of swallowing leads to GIabsorption as the primary route of absorption.” By this, we mean that asubstance that is dissolved in the mouth, but cannot be absorbed throughthe oral epithelium, may appear to be lingually delivered, but it isnot. The absorption is actually occurring through the digestive tractafter the substance has dissolved in the mouth and been swallowed (andis therefore typically less effective).

However, as mentioned, the lingual absorption of ALA, i.e., highconcentrations of ALA for relatively extended periods of time in theoral cavity (as opposed to swallowing as the primary method ofdelivery), has a negative side effect of oral burning or oral irritationand a somewhat unpleasant flavor.

The present limited-release invention addresses these negative effectsthrough the use of sucrose-based and non-sucrose-based candies, gums,and lozenges in various concentration and flavor combinations. Aflavored lingual/sublingual delivery system in the concentration rangeof 1%-6% thioctic acid (by mass), not only removes and/or minimizesthese effects, but it also improves the palatability of the raw compound(thioctic acid).

Provided that the lingual/sublingual delivery system is homogeneous, andthe thioctic acid concentration is within the preferred range, therelease of thioctic acid onto lingual surfaces is delayed and dispersedenough that the burn effect is overcome, especially within theconcentration range of 1-3% thioctic acid (by mass). This means an11-gram lozenge, candy, gum, or other lingual delivery system can beutilized to deliver 200 mg of thioctic acid without noticeable negativeeffects. Slightly greater concentrations of thioctic acid (up to the 6%range) can also be utilized without excessive negative effects; however,as the concentration increases so too does the burn effect.

To confirm, objectify, and increase the precision of our individualfindings on acceptable concentration levels of ALA in a lozenge, weperformed a study titled “The Oral Irritation or Burning due to ALAConcentrations in Buccal Applications” (Acceptability Study). Wedisclosed our test and data to the USPTO in connection with theprosecution of our U.S. patent application Ser. No. 13/602,093. In thistest, we provided ALA lozenges in three concentrations: 3%, 6% and 9%ALA (by weight). These hard candy sugar lozenges were cinnamon flavoredand weighed approximately 3 grams each. The lozenges had an asymmetric,shallow, essentially hemispherical shape, comprised of a 1-inch diametercircle on one side and a 0.3 inches deep hemisphere on the other side(the two sides meeting at the perimeter of the 1-inch diameter circle).The surface area of these lozenges was approximately the same surfacearea as a 6 g spherical lozenge. We say essentially hemispherical,because the mold that formed the lozenges is actually a polygon whoseflat facets approximate a hemisphere. The surface area of these lozengesis approximately 1.8 int.

Our findings were that the 3% ALA lozenge was acceptable, on average,for 85% of our 15-person test population. The 6% in ALA lozenge scoreswere neutral (i.e., a balance between acceptable and unacceptable). The9% ALA lozenge was, on average, 78% unacceptable.

Our findings provide a useful baseline of information to determine theconcentration of ALA acceptable for fairly typical lozenge in a lingualapplication.

Having established that higher concentrations of thioctic acid in alozenge or other lingual delivery systems increase the negative sideeffects, we must now consider the limitations of that data. While thereis a direct correlation, this assumption only holds true when thelingual delivery system and its matrix remain constant, i.e., theassumption is an oversimplification. It cannot be assumed that alllingual delivery systems and their matrices will dissolve at the samerate as each other. Additionally, increased surface area will increasethe rate of ALA delivery to the saliva. Therefore, we provide greaterspecificity of not only defining or limiting the range of ALAconcentration in the lingual delivery system, but also defining andlimiting the range(s) of the rate of ALA release from the lingualdelivery system into the oral cavity. To link acceptable, neutral, andunacceptable concentrations of ALA to ALA release rates, we firstestablish a baseline based on user data.

An in situ Oral Dissolution Trial used a 3% ALA, hard candy sugarlozenge having the same shallow hemispherical shape as the AcceptabilityStudy lozenge, hence a similar surface area. The lozenge was placed inthe mouth for one minute, taken out and weighed (for 30 seconds) andreturned to the mouth. This process was repeated until the lozenge fullydissolved in up to 10 minutes. The average trial weight of the lozengeswas 3.64 g. The average Peak ALA Release Rate (also the average maximumALA Release Rate) was 20.18 mg/min (column 7, titled “Release Rate(mg/min)”) which occurred between the one- and two-minute marks. See thedetailed chart below.

TABLE 1 In situ Oral Dissolution Trial Results (3.43 g Avg, 3% ALA, hardcandy sugar lozenge) Change mg ALA Release Time Weight Weight mg in Rate(min) (g) (g) % ALA ALA lost Solution (mg/min) 0 3.43 0 3 0 0.00 0.00 13.43 0.59 3 17.63 17.63 17.63 2 2.84 0.67 3 20.18 37.80 20.18 3 2.170.55 3 16.58 54.38 16.58 4 1.62 0.49 3 14.70 69.08 14.70 5 1.13 0.46 313.65 82.73 13.65 6 0.67 0.32 3 9.53 92.25 9.53 7 0.36 0.21 3 6.15 98.406.15 8 0.15 0.10 3 3.08 101.48 3.08 9 0.05 0.05 3 1.43 102.90 1.43

As seen in column 7 of the Oral Dissolution chart, the first minute ofdissolution (17.63 mg/min) does not provide the highest ALA releaserate. We believe this is due to the time required for a softeningprocess of the outer portion of matrix by the saliva prior to actualdissolution. In the second minute of dissolution, the Peak ALA ReleaseRate is reached at 20.18 mg/min. In the third minute of dissolution, therate drops to 16.58 mg/min and continues to descend in the subsequentminutes. Presumably, this is due to the decreasing surface area of thelozenge as it becomes smaller.

We note that the data from an individual lozenge did not always followthe exact progression of the averages. The first or third minute couldproduce a higher ALA Release Rate than the second minute of dissolution.This points to the issue that the amount of saliva, motion, abrasion,and physiological differences that naturally occurs in the mouth whensucking on a lozenge varies from person to person and, even with thesame person, from instance to instance. We will address this issuetowards the end of our disclosure by providing two methods of ex vivoALA Release Rate measurement utilizing (1) a USPC Type 2 PaddleApparatus or (2) a USPC Type 4 Flow-Through Cell Apparatus.

Note, column 6, titled “mg ALA in Solution” in the above OralDissolution Trial chart, is not actually relevant to the in-situ methodof measurement. It really reflects an ex vivo test where the ALA is notbeing removed from the saliva. In actual use, in situ, the ALA is (1)being removed from the saliva via the oral tissues and (2) being removedalong with saliva from the oral cavity by swallowing. If real timemeasurement of ALA in the saliva were possible, a more complex andnuanced picture would likely emerge. However, it is reasonable to assumethat that picture would still generally reflect, and correlate with, theALA Release Rates of column 7.

Linking the concentration of ALA in the lozenge to its Peak ALA ReleaseRate proceeds as follows. A 3% lozenge has a Peak Release Rate of 20mg/min; a 6% lozenge has a peak of 40 mg/min; and a 9% lozenge has apeak of 60 mg/min.

Accordingly, the Acceptability Study ALA percentages of 3%, 6% and 9%which had an acceptability rating of acceptable, neutral, andunacceptable, correlate to a Peak ALA Release Rates of 20 mg/min that isacceptable, 40 mg/min that is neutral, and 60 mg/min that isunacceptable.

However, the issue of acceptability is actually more complex. The degreeto which negative effects are considered excessive depends not only onthe ALA concentration in the lozenge, the ALA Release Rate and resultingALA levels in the saliva, but also on the context in which the ALA isbeing administered.

When a supplement or drug has side effects, the degree to which they areconsidered acceptable depends considerably on the severity of theproblem being alleviated. The acceptable negative side effects ofchemotherapy to treat cancer would not be acceptable for a vitamin beingtaken as a supplement. Meanwhile, the range of applications for thiocticacid is quite broad, ranging from an antioxidant health supplement to adiabetic neuropathy treatment (reduction of pain and other symptoms),and even extends to a treatment for life-threatening mushroom poisoning.Clearly, the ranges of acceptable negative side effects related tolingual ALA delivery (e.g., oral burning/irritation) depend on theparticular application.

To provide greater specificity on this issue, we have identified fivelevels of acceptability ranging from Agreeable to Tolerable. The levelsproceed from lower amounts of side effect (that are consideredacceptable) to higher. Each level is divided into two subcategories, a,and b, respectively representing everyday use and occasional (orintermittent) use. Level b would generally be expected to have a higherthreshold of acceptable negative side effects than level a, because theuser would experience the side effects less often. The categories aredetailed as follows.

Level-la is Agreeable for everyday prophylactic or supplemental use topromote health and for occasional use is level-1b. That is to say,Level-la represents an Agreeable response by the average user to arelatively low threshold of acceptable negative side effects in everydayuse.

Level-1b represents a presumed higher threshold of acceptable negativeside effects due to less frequent use.

Level-2a is Satisfactory for everyday use to mitigate or treat a healthproblem or disease and for occasional use the level is 2b.

Level-3a is Adequate for everyday use to reduce pain and for occasionaluse the level is 3b.

Level-4a is Preferable to IV for everyday use and for occasional use thelevel is 4b.

Level-5a is Tolerable for everyday use to improve very severe, orlife-threatening, medical conditions and for occasional use the level is5b. That is to say, Level-5a represents a Tolerable response, onaverage, to a high threshold of acceptable negative side effects ineveryday use. Level-5b represents the highest threshold of acceptablenegative side effects of all Levels because the use is occasional.

To reiterate, the maximum level of ALA concentration and consequent sideeffects that is acceptable at Level-5b is generally not acceptable atLevel-5a or the lower levels 4-1. The maximum level of ALA concentrationand consequent side effects that is acceptable at Level-4 is generallynot acceptable at Levels-3 or below, and so on.

The exact order of these levels, particularly level-4 “Preferable toIV”, may be different or altered based on feedback from subject use andtests.

Minor note: the maximum daily concentration and consequent negative sideeffect threshold would likely be unique for each Level, but we wouldexpect overlap below the maximum levels. For example, if a lozenge witha concentration of 1-3% ALA (and its resulting oral irritation) isacceptable for Level-1a and a lozenge with a concentration of 1-15% ALAis acceptable for Level-5b, then there is an overlap between the twoLevels in the 1-3% range.

Also, particular applications might span multiple Levels. For example,Levels 2, 3 and 4 could apply to diabetic neuropathy. And Levels 3, 4and 5 could apply to later stages of diabetic neuropathy. The resultinglexicon for referencing levels of acceptability may be utilized asfollows: Agreeable-1, Satisfactory-2, Adequate-3, Preferable-4,Tolerable-5. To specify sub level, denotation as follows: Agreeable-1a(or -1b), Satisfactory-2a (or -2b), Adequate-3a (or -3b), Preferable-4a(or -4b), Tolerable-5a (or -5b). Also, either Level or the adjectivename may be used interchangeably, e.g., Level-1 is the same asAgreeable-1.

A unique one-word adjective is also used to describe each Level, butwhen referring specifically to each Level by name it will be followed bya hyphen, the level number and, when distinguishing between daily andoccasional use, the sub level letter a or b, as follows: Agreeable-1,Satisfactory-2, Adequate-3, Preferable-4, Tolerable-5. To specify sublevel, denotation as follows: Agreeable-1a (or -1b), Satisfactory-2a (or-2b), Adequate-3a (or -3b), Preferable-4a (or -4b), Tolerable-5a (or-5b). Also, either Level or the adjective name may be usedinterchangeably, e.g., Level-1 is the same as Agreeable-1.

The next step is to connect these five Levels to the Peak ALA ReleaseRates. Based on our informal use, we would approximately correlateAgreeable-1 to the 20 mg/min rate; Acceptable-2 to 40 mg/min rate, andAdequate-3 or possibly Preferable-4 to 60 mg/min. We believe theacceptable side effects for Level Tolerable-5, particularlyTolerable-5b, exceeds the maximum 9% ALA concentration (and Peak ALARelease Rates of 60 mg/min) from the Acceptability Study. They maycorrespond to something closer to a 12% ALA concentration and 90 mg/minPeak ALA Release Rate.

However, more studies and test data are needed to truly define thecontextual acceptability of Peak ALA Release Rates in relation to thefive Levels. It is conceivable that a rate twice as high as the 60mg/min Peak ALA Release Rate would be considered tolerable by users atthe Tolerable-5b level. Accordingly, we furnish below Table 2 (in twoparts, a first portion column 1 through column 10 and a second portioncolumn 11 through column 18) to provide expected and/or possible PeakALA Release Rates that we expect to find after more acceptabilitytesting using the five different Levels of acceptability.

The below Table 2 starts with a range of ALA matrix concentration(“Matrix Conc.”) and ALA Release Rates (“Rate mg/min”) (based on theinitial Acceptability Study) in columns 1 and on the left (these firsttwo columns are also repeated in the continued table). The next twocolumns, 3 and 4, show what the ALA concentration and release rates arewhen increased by 110%. The successive columns continue to multiply theinitial ranges (columns 1 and 2) by increasingly larger percentages, upto 200% in in columns 15 and 16.

The last two columns, 17 and 18, show only ALA matrix concentrations.The reason for this is that ALA concentrations could be more than twicethe original amounts without increasing the Release Rates by the sameratio. That is because the rate at which the matrix dissolves could beslowed considerably by a variety of ingredients (as will be notedlater). Therefore, a lozenge or other lingual delivery system can bemade with a relatively higher concentration of ALA and still have arelatively lower ALA Release Rate.

TABLE 2 Maximum Acceptable ALA Matrix Concentrations and ALA ReleaseRates 1 2 3 4 5 6 7 8 9 10 Matrix Rate Conc. Rate Conc. Rate Conc. RateConc. Rate Conc. mg/min 110% 110% 120% 120% 130% 130% 140% 140% 1% 6.671.10% 7.33 1.20% 8.00 1.30% 8.67 1.40% 9.33 2% 13.33 2.20% 14.67 2.40%16.00 2.60% 17.33 2.80% 18.67 3% 20.00 3.30% 22.00 3.60% 24.00 3.90%26.00 4.20% 28.00 6% 40.00 6.60% 44.00 7.20% 48.00 7.80% 52.00 8.40%56.00 9% 60.00 9.90% 66.00 10.80% 72.00 11.70% 78.00 12.60% 84.00 1 2 1112 13 14 15 16 17 18 Matrix Rate Conc. Rate Conc. Rate Conc. Rate Conc.Rate Conc. mg/min 150% 150% 175% 175% 200% 200% 250% 300% 1% 6.67 1.50%10.00 1.75% 11.67 2.00% 13.33 2.50% 3.00% 2% 13.33 3.00% 20.00 3.50%23.33 4.00% 26.67 5.00% 6.00% 3% 20.00 4.50% 30.00 5.25% 35.00 6.00%40.00 7.50% 9.00% 6% 40.00 9.00% 60.00 10.50% 70.00 12.00% 80.00 15.00%18.00% 9% 60.00 13.50% 90.00 15.75% 105.00 18.00% 120.00 22.50% 27.00%

Having increased the specificity, and potential specificity, of themaximum ALA Matrix Concentration and ALA Release Rates, we now similarlyconsider their minimums.

At some point, the amount of ALA delivered to a person's bloodstream canbecome too small to be meaningful, typical, or measurable. Generally,the amount that is prophylactically useful as a supplement is smallerthan the amount required for the treatment of a disease. Beyond that, todetermine a minimum ALA Matrix Concentration, we must consider therelationship between concentration and the dose received.

A low ALA Matrix Concentration could still provide an effective amountof ALA. For example, 0.25% ALA Matrix Concentration delivered by thepreviously mentioned 11 g lozenge would still provide a dose of 27.5 mgof ALA. Because so much more lingual ALA enters the general bloodstreamthan ingested ALA, this dose is approximately equivalent to 100 mg ofingested ALA. 100 mg pills of ALA are quite typical in the currentmarket. This would suggest a dose that is half of that may still beserviceable; therefore a 0.125% ALA Matrix Concentration may be a validdose, particularly when used as a supplement. Because some amount ofexperimentation would be required to zero in on the exact amount, wehave outlined minimum balance of ALA Matrix concentrations and theirrelated ALA Release Rates in a Table 3 formatted similarly to Table 2.

Table 3 below discloses Minimum ALA Matrix Concentrations of 0.75%,0.50%, 0.25% and 1.25% and related ALA Release Rates. These amounts arethen decreased/increased by 8% and 15% in the subsequent columns. Thisyields a wider range of Minimum ALA Matrix Concentrations and MinimumALA Release Rates. Subsequent use, measurement, and experimentation willhelp determine the relevant minimums.

The minimum dose of ALA (and related ALA Matrix Concentrations and ALARelease Rates) that can be lingually administered and provide ameasurable amount of ALA in the blood stream (Minimum Measurable BloodALA) is of particular interest because it would be quite objective. Theminimum dose of ALA that can be lingually administered and provide ameaningful supplementation of ALA is a somewhat more subjective, albeitmore purposeful. Again, the minimums expected for a particular conditionor disease would likely be larger than the supplementation minimums.

TABLE 3 Minimum ALA Matrix Concentrations and ALA Release Rates 1 2 3 45 6 7 8 9 10 Matrix Rate Conc. Rate Conc. Rate Conc. Rate Conc. RateConc. mg/min 92% 92% 108% 108% 85% 85% 115% 115% 0.13% 0.83 0.12% 0.7670.14% 0.900 0.11% 0.71 0.14% 0.96 0.25% 1.67 0.23% 1.533 0.27% 1.8000.21% 1.42 0.29% 1.92 0.50% 3.33 0.46% 3.067 0.54% 3.600 0.43% 2.830.58% 3.83 0.75% 5.00 0.69% 4.600 0.81% 5.400 0.64% 4.25 0.86% 5.75

Tables 2 and 3 cover the range of ALA Matrix Concentrations and ALARelease Rates. For example, the largest ALA Matrix Concentration rangeamong column 1 values is 0.13% from Table 3 up to 9% in Table 2. Yet thelargest range of ALA Matrix Concentration anywhere, is from 0.1% inTable 3/column 7 going up to 27.00% in Table 2/column 18.

At the same time, the largest range of ALA Release Rates in column 2 isfrom 0.83 mg/min in Table 3 up to 60 mg/min in Table 2. Yet the largestrange of ALA Release Rates anywhere is from 0.71 mg/min in Table3/column 8 up to 120 mg/min in Table 2/column 16.

Therefore, a range of ALA Release Rates from 0.71 mg/min to 120 mg/minis a possibility, somewhat preferably ranging from 1.67 mg/min to 90mg/min; preferably 3.33 mg/min to 60 mg/min; more preferably 5.0 mg/minto 40 mg/min; and most preferably 6.67 mg/min to 20 mg/min.

As noted earlier, the Peak ALA Release Rate occurs in the earlierportion of the ALA lozenge's dissolution and is the maximum ALA ReleaseRate. In the later portion of the dissolution, the lozenge's surfacearea decreases and reduces the ALA Release Rate. This holds true only ifthe user is not chewing the lozenge, because that would break it intosmaller pieces (disintegration) and increase the total surface area.Depending on the degree to which the lozenge is broken up, this newsurface area amount could exceed the original surface area and cause ahigher Peak ALA Release Rate, thus becoming the new maximum ALA ReleaseRate. That in turn could potentially cause an unacceptable increase innegative side effects.

Compressed tablets, often used for lingual and/or sublingualapplications, have a similar problem of breaking up into smaller pieces,particularly as they approach the end of the dissolution process. Whenused as an ALA formulation, this could create the problem of producing aspike in ALA release and thereby creating a second Peak ALA Release Ratethat potentially exceeds the first Peak ALA Release Rate. To clarify,the first Peak ALA Release Rate results from only dissolution, while thesecond Peak ALA Release Rate is the result of disintegration anddissolution. However, the degree to which the tablet has alreadydiminished in size and surface area may render the issue ofdisintegration moot. Restated, if the second Peak ALA Release Rate doesnot exceed the first Peak ALA Release Rate, then the spike of ALArelease caused by the disintegration would not change the maximum ALARelease Rate and would not increase any negative side effects andtherefore would not be problematic.

The terms Sustained Release and Limited Release both refer to aformulation used for the lingual administration of active ingredient(s)that are slowly dissolved in the mouth. Because a second Peak ALARelease Rate does not exceed the first Peak ALA Release Rate, we areclassifying it as Sustained Release. For many active ingredients thatare lingually administrated, Sustained Release is acceptable becausethere is no significant negative side effect to a Release Rate spikethat increases the maximum Release Rate. In the case of ALA, a secondPeak ALA Release Rate that increases the maximum Peak ALA Release Ratemay cause negative side effects to increase from acceptable tounacceptable.

However, if the second Peak ALA Release Rate is higher than the firstPeak ALA Release Rate for the same compressed tablet or ALA formulation,possible solutions are lowering the ALA concentration or increasing thematrix dissolution rate, such that the second Peak ALA Release Ratefalls within acceptable parameters for the application.

Accordingly, a compressed tablet (formed by compressing the matrixingredients rather than melting them together with heat) may be a viableoption for the lingual administration of ALA. Despite the potentialdisintegration problems and possibly having a faster a matrixdissolution rate, the compressed tablet has the advantage of not usingheat. This would allow heat-sensitive ingredients other than ALA to beincorporated in the matrix. It may also be less expensive and/or easierto manufacture, and the necessary equipment may be more accessible tosome.

Returning to the hard candy lozenge as a version of the limited-releaselingual formulation, a key to its creation lies in the melting points ofsugar or isomalt relative to the sublimation temperature of thiocticacid. Since thioctic acid sublimates (i.e., goes from a solid to agaseous phase without turning into a liquid or breaking down) above 160degrees Celsius (C), and sucrose and isomalt formulations are commonlymade below this sublimation temperature, it is possible to add thiocticacid to molten sucrose or isomalt without changing the structure of thethioctic acid itself. Thus, a wide range of natural sugar or sugarsubstitute-based formulations are possible. During this process,thioctic acid can be combined with the molten release limiting matrixprior to the addition of secondary flavoring compounds or afterflavoring oils are added. For most other vitamins and drugs, thistemperature range would pose a problem.

The lozenge (typically hard candy) and the compressed tablet constitutethe most common formulations for lingual and/or sublingualadministration. There are other potential formulations for lingualadministration including caramels, gum, gummies (soft chewables), andliquid held in the mouth before swallowing; however, these are the notcommon lingual and/or sublingual formulations. Therefore, we will referto the lozenge and compressed tablet formulations as PrimaryFormulations and to the remaining formulations as SecondaryFormulations.

These Primary Formulations generally have a fairly simple shape, whichis solid, generally thick (i.e., stocky, compact, not thin) andgenerally an oblong shape or a circular (or approximately circular)disk. We will call these Primary Forms. These Primary Forms have agenerally low surface area to volume ratio, but not as low as aspherical shape which has the minimum surface area to volume ratio. Forgreater specificity, we define the Primary Forms as having a givenvolume lx (a First Volume) whose surface area (a First Surface Area) isless than, or equal to, a surface area (a Second Surface Area) of asphere whose volume (a Second Volume) is 2.2× (2.2 times as large theFirst Volume), wherein both forms (the Primary Form and the sphere) havethe same density (typically by being comprised of the same matrixmaterial). For example, a 4 g lozenge with a surface area to volumeratio equal to or less than an 8 g sphere (assuming identical matrixmaterial, therefore twice the volume equaling twice the mass) is aPrimary Form. In this example, the same would be true for a 5 g, 6 g,etc. lozenge; but not a 2 g or 3 g lozenge.

Other forms have larger ratios of surface area to volume, particularlyshapes that are thin or elongated such as a stick of gum, convolutedshapes, or shapes with a single or multiple interior cavity(ies), all ofwhich we will call Secondary Forms.

To put it very simply, or in more layman-type terms, most typicallozenges and compressed tablets in current use for lingual and/orsublingual administration are Primary Formulations and have PrimaryForms.

There is one Secondary Form that is of particular interest to us: thetorus shape. As a hard candy, the torus shape (similar to a disk with ahole in the center) is probably best exemplified by the LIFE SAVERS®brand candy. The advantage of the torus shape for our application isthat the difference between the initial surface area before dissolutionand the diminishing surface area during dissolution is less pronounced.

Compared to a solid cylinder shape typical of lozenges and tablets, atorus shape with similar outside dimensions will have a larger surfacearea. This is not particularly beneficial but maintaining a largersurface area during dissolution is helpful. An ideal ALA Release Ratewould not have a significant peak, but rather maintain a fairly constantrelease rate. The torus shape could provide an ALA Release Rate that ismore consistent than a simple non-torus solid disc shape.

To clarify, a torus is defined as a ring-shaped surface generated byrotating a circle around an axis that does not intersect the circle. Wedo not mean the definition to be quite this precise. The ring-shapedsurface could be generated by rotating a circle or some othercross-section shape such as a square, square with large radii corners,or triangle, pentagon, hexagon etc., or some asymmetric variation of theshapes. Also, the rotation around the axis would not have to be circularbut could be elliptical (as viewed from above), square or some othergeometric shape including those just noted above. The main point is thatthe otherwise solid shape as a hole through the center that allows thedissolution of the matrix on the outside surfaces (of the otherwisesolid shape) as well as the “inside” surfaces defined by the hole. Usingmore than a single hole could also be an option, however this wouldincrease the initial surface area even more.

Another name for our formulation, intended for Oral Dissolution &Transmission, is AlphaBon™. When the AlphaBon formulation is a lozenge,we then refer to it as an AlphaBon™ lozenge. When the formulation is acompressed tablet, we then refer to it as an AlphaBon™ tablet, and soon.

The ALA lozenges used in the in situ Oral Dissolution Trial of TABLE 1have a surface area of approximately 1.8 in². Given a tolerance range ofabout 10%, this would translate into a range of 1.6 to 2.0 in². Given atolerance range of about 20%, this would translate into a range of 1.4to 2.2 in².

The ALA lozenges used in the in situ Oral Dissolution Trial of TABLE 1have a hard candy sugar matrix whose formulation is described in thesection titled, “SUCROSE Based Lingual Thioctic Acid ManufacturingProcess (Small Scale)”. This hard candy sugar matrix will dissolve at agiven rate which can be determined by experimentation.

A range of ALA Dissolution Rates can be specified as an ALA formulationhaving a Dissolution Rate similar to a particular ALA hard candy sugarlozenge as now described. Such particular lozenge would be made by theaforementioned Sucrose Based Manufacturing Process with a surface arearanging between 1.4 and 2.2 in², preferably between 1.6 and 2.0 in in²,or most preferably 1.8 in²; and such particular lozenge ranging in ALAconcentrations as described between those described in Table 3 (Columns1, 3, 5, 7, 9) and Table 2 (Columns 1, 3, 5, 7, 9, 11, 13, 15). Thisrange of ALA concentration would specifically include possibly from0.11% to 18%, preferably from 0.25% to 12%, more preferably 0.50% to 9%,and most preferably 1% to 6%.

We disclose a further aspect of our limited release lingual/sublingualdelivery systems for thioctic acid regarding localized ALAconcentrations verses the entire oral cavity. As ALA is released fromour formulation, it is inherently present at a higher concentrationadjacent to the formulation itself as the ALA dissipates into the restof the saliva and into other portions of the oral cavity. For thisreason, we recommend moving the formulation to different parts of themouth, particularly from cheek to cheek and underneath the tongue duringdissolution to prevent excessive buildup of ALA in any single area. Thisis particularly relevant to any portions of oral tissue in directcontact with the formulation. The ALA is the most concentrated therebecause it does not have the space to dissipate easily. For this reason,buccal patches (or thin-film delivery systems) are unsuitable, and,also, because they are designed for rapid release of the activeingredient. Such release could possibly lead to sores as an apoptoticburn may occur on the inner cheek, or other oral tissues, due to thetissues experiencing a more concentrated and more sustained ALAexposure.

We further disclose that thioctic acid is co-transported into cellsalong with glucose. This means that mechanisms for thioctic acidabsorption exist in the buccal cavity, where sugar is readily absorbed.Therefore, unlike many lingual/sublingual vitamins and supplements,faster and more complete absorption into oral tissues of thioctic acidcan occur in the mouth, because of the co-presence of sugar in thesaliva. Not all lingual/sublingual delivery systems are effective.Instead, the act of swallowing leads to GI absorption as the primaryroute of absorption.

We are unaware of any published studies that conclusively indicate thatALA is co-transported along with glucose or fructose from the oralcavity into the bloodstream but based on our own experience with lingualALA lozenges, we believe this is the case. We believe that many or mostnatural sugars are actively transported from the saliva, through theoral membranes, and into the bloodstream. Furthermore, we believe thatALA is transported along with these sugars.

We have noticed that a given concentration of ALA in an isomalt (anartificial sugar) matrix has a stronger burning sensation compared to asimilar concentration of ALA with glucose, fructose, or sucrose-basedmatrix. While there are other mechanisms that might explain this, webelieve that glucose, fructose, or sucrose may assist in the activetransport of ALA across the oral membranes. Furthermore, it may be thatthis occurs with other natural sugars such as monosaccharides, includinggalactose; disaccharides, including lactose and maltose; and possiblysome oligosaccharides. We presume that this does not occur withartificial sugars, because the active transport mechanism would notrecognize or be able to interact with these molecules.

There is a twofold advantage to faster transport of ALA across the oralmembranes. The first is more rapid removal of ALA from saliva. Thisreduction of ALA concentration reduces its burning side effect. In turn,this could allow for a higher ALA Release Rates without increasing ALAconcentrations in the saliva. The second advantage is that the ALA getsinto the bloodstream faster, which can improve peak concentrations ofALA in the bloodstream.

These two advantages work together synergistically. If ALA moves morerapidly from saliva, then it is possible to increase the amount of ALAin the formulation, resulting in higher ALA Release Rates. Then, moreALA can be released into the saliva, which in turn could furtherincrease the rate at which ALA enters the bloodstream, which in turnincreases the peak concentrations of ALA in the bloodstream. Restated,if (1) the rate-limiting step during lingual administration of ALA isthe transition process from saliva through the oral membranes, to thebloodstream; and (2) glucose, fructose or natural sugars increase thisstep; then (3) the final goal of higher peak concentrations of ALA inthe bloodstream can be achieved due to the presence of a matrix withsuch sugar. Additionally, it is easy for such sugar to be a part of theformulation. It is also a simple matter to adjust the ALA concentrationof the formulation to increase or decrease its release rate.

The goal of higher peak concentrations of ALA in the bloodstream bearsfurther discussion.

Importantly, data on the pharmacokinetics of thioctic acid in diabetesand other pathological states implies that peak plasma levels andpercent utilization (based upon an area under the curve analysis) may bemore important than specific oral doses. Based upon this assumption, anddata that shows superior peak plasma levels for limited release lingualversus GI absorption delivery systems, limited-release lingual deliverysystems are expected to be more effective than GI delivery systems,Thus, IV-like beneficial effects using this limited-release lingualdelivery system are actually expected to exist at a range of 300-600 mgthioctic acid, which equates to a lozenge-like formulation with a totalmass of only 18-36 g. It is impossible to achieve the same IV-equivalentplasma levels in GI delivery systems without deleterious side effectsassociated with such high doses.

Aside from these deleterious side effects, it is not possible for GIdelivery systems to achieve the high peak ALA plasma levels of IV or ourlimited-release lingual delivery systems, because the GI delivery is aninherently slower overall process.

One of the side effects observed during IV delivery of thioctic acid isa hypoglycemic response. For this reason, even for diabetics, glucose iscommonly added to the IV mixture. This hypoglycemic response has neverbeen reported for existing oral delivery systems. However, duringinitial testing of the limited-release lingual delivery system, asignificant number of test subjects experienced this hypoglycemicresponse. Therefore, not only are IV plasma levels obtained by thelimited-release lingual delivery system, but associated side effects aswell. This implies the same therapeutic effects obtained during IVdelivery can be expected during clinical trials.

This highlights yet another advantage of glucose, fructose, sucrose, andpresumably other natural sugars. Not only can they assist in thetransfer of ALA from the saliva to the bloodstream and thereby reducethe negative side effects of oral burning, but they can also reduce thenegative side effect of hypoglycemia once the ALA is in the bloodstream.This is a further synergy. As discussed earlier, sugar can play a rolein increasing the peak concentration of ALA in the bloodstream; now wesee it also can assist in the side effects from that peak concentration.

However, many diabetic patients placed under thioctic acid therapy mightbe uncomfortable with a sucrose-based delivery system. Therefore, asugar-free version of the lingual delivery system was created, usingisomalt in the place of sucrose. This isomalt variation shows the samebasic characteristics as the sucrose formulation originally tested. Thatis to say, the isomalt formulations can achieve similar high peakconcentrations of ALA in the bloodstream and presumably other sugar-free(i.e., sugar substitute or artificial sugar) formulations as well.

In both the sucrose and sugar-free formulations tested, the release ofthioctic acid from the dispersal medium occurs slowly, as the lingualdelivery formulation dissolves. Thus, thioctic acid is spread acrosslingual surfaces in local concentrations that remain low at any givenmoment. This means that the cellular burn described above is minimized,and thioctic acid can be quickly delivered to systemic circulation indoses that reach high plasma concentrations (especially in comparison toGI absorption levels) without flooding local cells.

In other words, our limited-release lingual/sublingual delivery systemsfor thioctic acid achieves two important objectives simultaneously: theformulation can release ALA slowly enough to prevent burning or undoirritation of the oral tissues and, at the same time, the ALA ReleaseRate is fast enough to provide high peak plasma levels in thebloodstream.

The rate at which the limited release lingual/sublingual delivery systemdissolves in the mouth is not a simple matter of dissolving the matrixin water. The mouth contains specific enzymes that are designed to breakdown complex sugars, as well as mechanisms for the absorption of simplesugars. Accordingly, including substances that inhibit enzymic breakdownof the matrix will slow the rate of dissolution and thus affect therelative concentration in the mouth. An obvious example is the isomaltmatrix itself, which contains a synthetic sugar related to sucrose whichcannot be cleaved into glucose and fructose due to the inverted natureof its covalent bond. This matrix, at least theoretically, dissolvesslower in the mouth than the sucrose-based matrix. Thus, the isomaltmatrix itself may be a slight inhibitor of thioctic acid release.

To any of the above-mentioned formulations, the addition of specificcompounds that inhibit the rate of breakdown is intended. Because thereare no specific enzymes in the mouth responsible for breaking downproteins and long chain lipids, these ingredients will further limit therelease of thioctic acid into the mouth, overcoming the apoptotic burn,while enabling lingual absorption mechanisms to bypass the first passmechanism of the liver. A few specific examples include lecithin,glycine, potassium bitartrate (cream of tartar), protein hydrolysate,hydrolyzed collagen, linolenic acid, and/or other food-grade proteinsand fatty acids.

As mentioned earlier, these dissolution-slowing substances would allowhigher concentrations of ALA in a given formulation without increasingthe ALA Release Rate. This highlights that, both in optimizing deliveryand minimizing side effects, the ALA Release Rate supersedes the actualconcentration of ALA in the formulation.

Preliminary data obtained during formulation testing (see below formanufacturing details) shows that a 2% thioctic acid concentrationformulation of 600 mg reaches a peak plasma level of 2,070 ng 15 minutesafter the isomalt lozenge is placed into the mouth. In comparison, anequivalent dose of an orally administered tablet reaches a peak level of840 ng in 60 minutes. Of particular note is the fact that IV doseswithin the same dose range and tested by the same methods, reached peakplasma levels of 1,900 ng, since high IV plasma levels are required formaximum benefit. Given this information, and the high peak levelslingual formulations are able to achieve, lingual dosing is likely toprove therapeutically equivalent to IV dosing and negate the need forinvasive needles and expensive medical monitoring when a patient isentered into thioctic acid treatment regimes.

It should be noted that the formulation tests to determine these peakplasma levels were obtained with relatively few subjects and samples.Therefore, there is a level of variability and imprecision in thenumbers. The significance of the test is chiefly that our lingual ALAformulation had results that are much closer to the IV plasma levelswhen compared to the orally administrative tablet (ingested).

One way to regard this is that it would be a significant improvement onexisting ALA delivery systems if our lingual formulation achieves peakplasma levels of ALA more similar to those of IV delivery than ingesteddelivery. For example, considering the ALA plasma levels of 1,900 ng forIV and 840 ng for ingested, if our ALA formulation achieved an ALAplasma level greater than 1,370 ng, then its plasma level would be moresimilar to that of an IV and less similar to that of ingested ALAadministration.

Another way of defining this would be to say that 1,370 ng is 72.11% of1,900 ng, so it would be a significant improvement on existing ALAdelivery systems if our lingual formulation achieves peak plasma levelsof ALA within 27.89% of the peak ALA plasma levels of IV delivery.

Therefore, it is somewhat less substantial, but still a modestlysignificant improvement on existing ALA delivery systems, if our lingualformulation achieves peak plasma levels of ALA within 30% or 35% of thepeak ALA plasma levels of IV delivery. It is an even more significantimprovement on existing ALA delivery systems if our lingual formulationachieves peak plasma levels of ALA within 25% or 20% of the peak ALAplasma levels attained by IV delivery.

Finally, it is an extraordinary improvement on existing ALA deliverysystems if our lingual formulation achieves peak plasma levels of ALAwithin 15%, 10% or 5% of the peak ALA plasma levels achieved by IVdelivery. Because our test results for the lingual formulation of 2,070ng exceeded the IV results (1,900) by about 8%, we estimate the amountof experimental and measurement error is likely 10% to 15%. Therefore,we believe our results show that our lingual ALA formulation morerealistically falls within the range of plus/minus 10% or 15% of thatachieved by IV. It is conceivable, however, that more testing will showour lingual formulation achieves peak plasma levels of ALA within any ofthe above-mentioned percentages of peak ALA plasma levels from IVdelivery.

The present invention includes the use of lingual and sublingualdelivery systems for thioctic acid, wherein the delivery system iseither sucrose or non-sucrose based. The limited-releaselingual/sublingual delivery system may be a lozenge, gum, or otherrelease-limiting matrix formulation placed in the patient's mouth andintended to remain in the mouth. The formulation contains aconcentration of thioctic acid between 1% and 25% by mass, preferably ata concentration of 1% and 9%, more preferably 1% and 6%, even morepreferably 1% and 3% and most preferably at approximately 2% (plus/minus½% so 1½% and 2½%) by mass.

The formulation's matrix, also known as a diffusion-limiting bindingagent, either hard or soft, in the lingual/sublingual formulations mayinclude, but are not limited to sucrose, isomalt, dextrose(glucose),fructose, lactitol, sorbitol, maltose and chicle.

Inactive ingredient variations in the lingual/sublingual formulationsmay include but are not limited to hydrogenated starch, hydrolysate,gluconic acid, malic acid, lactic acid, sodium lactate, aspartame,glycine, corn syrup, lecithin, cream of tartar, honey, fruit juices,vegetable juices, water, and flavoring oils or alcohols.

Active ingredients in addition to thioctic acid may include (but are notlimited to): Selenium, Vitamin E, Vitamin C, Chromium, Potassium,Calcium, gamma-linolenic acid, myoinositol, Vitamin B, Coenzyme Q, andvarious herbal extracts, including, but not limited to, cinnamon,chamomile, marshmallow, anise, eucalyptus, peppermint, elder, fennel,licorice, rose hips, sage, and thyme.

Individual lozenges, candies, or other lingual delivery systems areexpected to be from 1.0 g to 30.0 g, with thioctic acid dose variationsbetween 10 mg to 600 mg. However, extremely low-dose variations (from5.0 mg to 10 mg) of thioctic acid are anticipated, such that lozengesfor general consumption as a supplement are included in addition to thehigh-dose formulations intended for specific therapeutic effects. Thesetherapeutic applications may include the treatment of Alzheimer's,diabetic peripheral neuropathies, retinal neuropathies, and otherphysiological states where thioctic acid therapy is advised or underinvestigation.

The term dose can be somewhat unclear. It can mean the amount of activeingredient in a single lozenge, tablet, or other formulation. It canmean the amount of active ingredient administered in a short period oftime, for example taking two aspirin together. Or it could mean theamount of active ingredient administered over a longer period of timesuch as a day.

The context of use often clarifies the meaning; however, it is worthclarifying our use of it. Unless otherwise specified, we mean dose torefer to a single lozenge, tablet, or other unit of formulation. Torefer to it specifically, we will use the term Unit-Dose. To refer totwo or more lozenges, tablets, or other units of formulation, takentogether or in relatively rapid sequence, we will use the termMulti-Dose, or for more specific numbers, Double-Dose, Triple-Dose etc.

When using the term dose to refer to a longer period of time, such as aday, where individual unit-doses are taken intermittently, we will usethe term Total-Dose or for a particular unit of time, Daily-Dose,Weekly-Dose, etc.

The previously mentioned individual lozenges or other lingual deliverysystems with thioctic acid dose variations between 10 mg to 600 mg (or 5mg to 600 mg) refer primarily to a Unit-Dose. Yet the 5 mg or 10 mg to600 mg dose could also refer to a Multi-Dose scenario. If lozenges,tablets, or other units of formulation are quite small, then multipleunits could be taken simultaneously.

For example, five, 0.5 g lozenges, each containing 2 mg of ALA, couldmake a 10 mg ALA Multi-Dose. Or 10, 0.1 g lozenges, each containing 0.5mg of ALA, could make a 5 mg ALA Multi-Dose.

Therefore, we extend the range for individual lozenges, tablets, orother formulations to sizes below 1.0 g if in aggregate they may bereasonably taken as a Multi-Dose that equals 1.0 g or more. Furthermore,we extend the range for individual lozenges, tablets, or otherformulations to doses of ALA below 5 mg if in aggregate they may bereasonably taken as a Multi-Dose that equals 5 mg or more.

As noted in Table 3 and related discussion, concentrations below 1% arepossible and acceptable in terms of preventing thioctic acid burn.However, the issue of having enough thioctic acid to deliver ameaningful dose becomes an issue. It would be reasonable to assume thatsmaller Unit-Doses, such as 30 mg per day, would still provide somebeneficial effects. 30 mg per day spread out over six Unit-Doses (onebefore and after each meal) would result in a Unit-Dose of 5 mg.Accordingly, even doses as small as 5 mg, to be taken multiple timesduring the course of the day may provide an effective dose to act as ameaningful maintenance level or prophylactic level of thioctic acidsupplementation.

It is worth remembering that smaller Unit-Doses and Total-Doses of ALA(compared to typical ALA doses that are ingested) are possible becausethe lingual delivery of ALA results in higher peak plasma levels of ALA.Also, small Unit-Doses and Total-Doses of ALA could be meaningful,prophylactically or as a treatment, for the mouth, oral tissues or othernearby tissues, because the ALA concentration levels would be expectedto be higher in those areas proximal to the ALA release.

For those therapeutic or supplementation purposes in which RLA isbelieved to be exclusively or primarily effective, the dose mighttheoretically be cut by 50% for the same effective dose as racemic ALA(or possibly by 25% if SLA interferes with RLA utilization).Accordingly, the low end of the concentration range discussed in thispatent should be read to represent values that are multiplied by afactor of 50% (or possibly 25%) when using the possibly more effectivethioctic acid enantiomer. The same is true for minimum milligrams ofdosing. For example, the 5 mg minimum listed for thioctic acid would bereduced to 2.5 mg (or possibly 1.25 mg). Thus, in cases where thetheoretically more active enantiomer is utilized, the minimumconcentration range of 1% thioctic acid would actually reflect a minimumconcentration range of 0.5% (or 0.25%) when that enantiomer is usedalone in the limited release lingual system.

Exemplary Preparations of Hard Candy Lozenge Formulations Preparation 1

In a stainless-steel saucepan, add 1.0 cup of sugar (185 g), ½ cup lightcorn syrup (148 g), and ¼ cup of water (64 g). Using a candythermometer, heat the mixture up to 300 degrees Fahrenheit, stirringoccasionally with a stainless-steel spoon.

As soon as the correct temperature is reached, add ¼ teaspoon (1.3 g)red food coloring, and ½ teaspoon (2.7 g) of cinnamon oil. Mix incompletely (avoid stirring too much or candy will become a sugary lump).

Remove from heat and add 10 g of Thioctic acid. Prior to adding the rawthioctic acid, ensure it is finely powdered with a mortar and pestle.This will make it easier to ensure a homogeneous mixture is obtained.Quickly mix in completely, ensuring that the mixture becomes homogeneous(lumps or specks will result in a matrix that has a high concentrationin small pockets, which can cause problems during administration).Perform this step in a well-ventilated area, since a small fraction ofthe thioctic acid will sublimate.

To minimize the thioctic acid sublimation, the ALA may be added aftercooling down the molten matrix to a temperature below 300 degreesFahrenheit, such as a temperature (in Fahrenheit) ranging from 280degrees to 275 degrees, but preferably 275 degrees to 265 degrees, ormore preferably 265 degrees to 255 degrees, and most preferably 255degrees to 245 degrees. The lowest temperature that can be used whilestill providing sufficient time and/or temperature to thoroughly mix theALA into the matrix is likely the best, unless the ALA sublimation isnegligible under a given temperature, say 270 degrees Fahrenheit, andfurther lowering the matrix temperature before adding ALA would besuperfluous.

Immediately pour into hard candy molds that have been lightly coatedwith vegetable oil (this makes it easier to remove the candy once it hascooled). Let cool completely.

Dust with powdered sugar. This minimizes water absorption during storageand keeps the pieces from sticking together. Store at room temperatureaway from direct sunlight in sealed baggies or Tupperware containers.For clinical studies, place each lozenge in its own blister packcompartment.

The above recipe yields a 2.5% thioctic acid limited release lingualhard candy lozenge. Exact dosage will depend upon the size of the moldsutilized.

Preparation 2

In a stainless-steel saucepan add 1.0 cup of Isomalt (185 g), and 4tablespoons of water (60 g). Using a candy thermometer, heat the mixtureup to 300 degrees Fahrenheit, stirring occasionally.

As soon as correct temperature is reached, add ¼ teaspoon (1.3 g) redfood coloring, and ½ teaspoon (2.7 g) of cinnamon oil. Mix in completely(avoid stirring too much or candy will become a sugary lump).

Remove from heat and add 6.5 g of Thioctic acid. Prior to adding the rawthioctic acid, ensure it is finely powdered with a mortar and pestle.This will make it easier to ensure a homogeneous mixture is obtained.Quickly mix in completely, ensuring that mixture becomes homogeneous(lumps or specks will result in a matrix that has a high concentrationin small pockets, which can cause problems during administration).Perform this step in a well-ventilated area, since a small fraction ofthe thioctic acid will sublimate.

To minimize the thioctic acid sublimation, the ALA may be added aftercooling down the molten matrix to a temperature below 300 degrees(Fahrenheit), such as a temperature (in Fahrenheit) ranging from 280degrees to 275 degrees, but preferably 275 degrees to 265 degrees, ormore preferably 265 degrees to 255 degrees and most preferably 255degrees to 245 degrees. The lowest temperature that can be used whilestill providing sufficient time and/or temperature to thoroughly mix theALA into the matrix is likely the best, unless the ALA sublimation isnegligible under a given temperature, say 270 degrees. Fahrenheit, andfurther lowering the matrix temperature before adding ALA would besuperfluous.

Immediately pour into hard candy molds that have been lightly coatedwith vegetable oil (this makes it easier to remove the candy once it hascooled). Let cool completely.

Store at room temperature away from direct sunlight in sealed baggies,Tupperware containers, or individual blister packs.

The above recipe yields a 2.6% thioctic acid limited release sugar-freelozenge.

Standard Operation Procedures for Lingual Thioctic Acid Release RateAnalysis (1) Synopsis of the Lingual Lozenge Dissolution Rate TestingProtocol

Preliminary in situ testing has revealed an average oral dissolutiontime of approximately 8-10 minutes for a hard candy sugar matrix ALA(AlphaBon™) lozenge weighing an average of 3.4 grams, comprising 3%thioctic acid, with the shape of such lozenge having an approximately0.28-inch-deep hemispherical, or approximately hemispherical, shape onone side and a flat disc (or polygon) of approximately 1 inch indiameter on the other side or face. To clarify, the lozenge is formed bypouring the molten sugar/ALA matrix into an approximately hemisphericalmold, such that the flat disc portion is the top surface of the matrixflowing/pooling to form a flat face). Further in situ testing will beperformed to obtain an oral dissolution time that more preciselyreflects an average of larger number of subjects.

A description of this type of in situ dissolution analysis is described,wherein the release rate can be indirectly determined by the dissolutionrate of the lozenge. This type of dissolution testing can be performedex vivo with artificial salvia to determine more consistent dissolutionrates than those expected to occur in situ due to physiologicaldifferences between subjects. This is specified in the protocol below.

Furthermore, in order to more closely match the average in situdissolution rate to the conditions used during ex vivo release ratetesting the USPC Testing Apparatus to be utilized (Type 2 or Type 4)should be set to an RPM and/or flow rate that allows a similardissolution time to occur.

To this end, artificial saliva as specified in the detailed sectionbelow is utilized as the solvent solution, with a temperature of 35degrees C. (+/−0.5 degrees C.). Initial flow rate conditions are set at6.0 mL/min and/or an initial paddle speed of 50 RPM. An ALA formulationis then placed within the relevant testing apparatus and the time forfull dissolution to occur is recorded. No samples are obtained duringthis procedure and all post apparatus solutions are discarded.

The paddle speed and/or flow rate on the testing apparatus is thenincreased (or decreased) by a factor that reflects the difference indissolution time between that obtained ex vivo and that seen in situ,such that subsequent runs of the same procedure are repeated until theex vivo rate of dissolution most closely matches that observed in situ.

However, it is understood that it may not be possible to fully match thedissolution time observed ex vivo due to the limitations of the testingapparatus and experimental conditions in matching those actuallyoccurring in vivo (i.e., a lack of tongue mechanical action; factorsspecific to the artificial saliva solution; oral mucosal removal ratesaffecting the removal of thioctic acid and/or sucrose; and the presenceor absence of enzymes such that diffusion is affected; etc.), in whichcase the maximum flow rate to be utilized in order to obtain a givenrelease rate should be 15 mL/min. Flow rate speeds above this maximumthreshold are expected to distort the concentration of samples obtainedand should be avoided. Similarly, the maximum paddle speed is 150 RPM.

Defining In Vivo TEST

If the dissolution times observed ex vivo cannot match those actuallyoccurring in vivo due to any of these limitations, then in vivo testingmust take precedence.

Also, an in vivo study may be simpler or less expensive and maytherefore be a preferred or an initial method to determine ifformulation falls within a given range of ALA Dissolution Rates.

To determine if a formulation falls within a given range of ALADissolution Rates, using an in vivo study, at least 12 subjects eachtested three times (three lozenges) must be utilized resulting in 36results to be averaged. The test procedure is as follows: the lozenge isplaced in the mouth for one minute, taken out and weighed (for 30seconds), and returned to the mouth. This process is then repeated untilthe lozenge is fully dissolved.

If the results of such a study are challenged by another party and theyperform a second in vivo study which finds different results, such thatthe two studies disagree as to whether such formulation falls withinsuch ALA Dissolution Rate range, then a third study may be performed.Such third study to be performed by a third-party, using twice as manysubjects (24), each tested three times, resulting in 72 data points.

The results of any of these in vivo studies must be statisticallysignificant to determine a valid maximum ALA Dissolution Rate for anygiven formulation.

In the absence of an ex vivo test that can replicate in vivo maximum ALADissolution Rates, is more meaningful, more statistically significant,and has a substantially lower standard deviation, such average maximumALA Dissolution Rate(s) determined by such third study will beconsidered definitive.

(2) Synopsis of the Lingual Lozenge Release Rate Concentration TestingProtocol(s)

If a USPC Type 2 Paddle Apparatus is utilized it should conform to thefollowing specifications: 25-150 RPM Paddle Speed, 35 degrees Celsius(C). (+/−0.5 degrees C.).

If a USPC Type 4 Flow-Through Cell Apparatus is utilized it shouldconform to the following specifications: 3.0-15.0 mL/min, 35 degrees C.(+/−0.5 degrees C.).

For both apparatus, the flow rate and/or paddle speed are set to thatdetermined to be ideal via dissolution testing and the temperature isset to 35 degrees C. (+/−0.5 degrees C.). After equilibrium, an initialsample is taken of the solvent contents of the apparatus and then theALA formulation is placed in the apparatus and a total of 10 samples areobtained, each at an equal fraction of the total dissolution time.

For example, given a total dissolution time of 10 minutes a blank sampleis first obtained, then samples taken at 60 second intervals. At thispoint the lozenge should be fully dissolved. If the dissolution is 20minutes, then samples would be taken at 2-minute intervals.

In all cases the sampling time interval should fully encompass theintroduction of the ALA formulation into the testing apparatus and itscomplete dissolution. If more than 10 samples are needed for thisprocess, then more samples should be obtained. Under no condition shouldsamples be taken in less than 30 second intervals, nor more than 3minutes apart.

It should be noted that gum based thioctic acid delivery systems willnot produce the same release profile as lozenges and tablets utilizingeither the Type 2 or Type 4 dissolution apparatus. In the event thatthese types of formulations are examined, a gum-specific dissolutiondevise will be required. Several have recently been patented butwide-spread commercial availability is still lacking. If this system isrequired, the same artificial saliva should be used as the dissolutionmedium, at the same temperature, such that only variations in apparatussetup will exist between the new apparatus and the apparatuses discussedin this protocol.

(3) Synopsis of the Thioctic Acid HPLC/ECD Concentration TestingProtocol

20 μL of each time point sample (resulting from the USPC Type 2 or Type4 apparatus utilized during the creation of individual release ratesamples) are injected into a HPLC which utilizes a mobile phase bufferthat is 50% acetonitrile in 0.05 M potassium dihydrogen Phosphate,adjusted to a pH of 2.5 with phosphoric acid.

The HPLC itself should utilize a guard column and a Nucleosil 120-C18 5pm column, with a flow rate set at 1.0 mL per minute. An electrochemicaldetector equipped with a glassy carbon electrode set at a potential of+/−1.1 V should be used to quantify the results, with a detection limitof approximately 5 ng/mL. For this protocol, a range of 2.0 pA isadvised, with a filter setting of 0.10 Hertz.

To calibrate the HPLC/detector for a given experimental run, freshlipoic acid standards and samples must be prepared on the day of theexperiment to avoid drift effects. Under these experimental conditions,the retention time for lipoic acid is approximately eight minutes; ifpure Acetonitrile is used, the exact retention time for any particularequipment setup will be obvious, since following the initial solventfront (which appears early) will be a delayed, distinct lipoic peak (asecond, more diluted standard can also be used to more fully calibratethe detector).

If a good quality integrator is used, the reported area under a givenpeak can be used to evaluate the results. However, if the integrator isunreliable the height of each lipoic peak can be measured by caliper toobtain the same basic results. In either case, to quantify thedetector's behavior on a given day standards should be run before,during, and after the samples, and subsequently averaged to obtain anarea reported per pg (or mm per pg) value for quantitative analysis.

Specific Details of the ALA Formulation Dissolution Protocol

TABLE 4 Solvent for AlphaBon ™ Dissolution Rate and Thioctic AcidRelease Rate Testing KH₂PO₄  2.5 mMol/L (Monopotassium Phosphate) Na₂PO₄ 2.4 mMol/L (Disodium Phosphate) KHCO₃ 15.0 mMol/L (PotassiumBicarbonate) NaCl 10.0 mMol/L (Sodium Chloride) Solvent for AlphaBon ™Dissolution Rate and Thioctic Acid Release Rate Testing: ArtificialSaliva MgCl₂  1.5 mMol/L (Magnesium Chloride) CaCl₂  1.5 mMol/L (CalciumChloride) Citric Acid 0.15 mMol/L (Distilled water to volume)pH adjusted to 6.7 with NaOH or HCl.

A) Determination of Release Rate Acquired by Dissolution Measurements:(In Situ Dissolution Analysis)

When considering the thioctic acid release rate of a solid lozenge (orformulation) several factors will affect the rate of release, the mostobvious being the homogeneity of the matrix in which thioctic acid ispresent, the initial thioctic acid concentration of the matrix, thecomposition of the matrix itself, and the surface area.

If the matrix is truly homogeneous and the initial concentration ofthioctic acid within a lozenge is known at the start of the dissolutionprocess, a determination of mass change over time can be indirectlyrelated to the amount of thioctic acid released within a given timeframe. This will hold true for a wide range of possible matrixesprovided the lozenge in question is homogeneous. For non-homogenousmatrixes direct measurements need to be obtained, such that an indirectdetermination of the thioctic acid release rate as explained below isbelieved to be invalid.

By definition, the concentration of thioctic acid ([ALA]) in a givenlozenge is a measure of the mass of ALA present divided by the totalmass of the lozenge {(Mass of ALA)/(Total Mass of the Lozenge)}. Thus,the release of ALA at a given moment is a direct reflection of thechange in lozenge mass; see equation #1 below.

$\begin{matrix}{M^{T_{ALA}} = {{\left( {M_{{Lo}\; 2}^{i} - M_{{Lo}\; 2}^{f}} \right)*\left( \underset{\_}{M_{ALA}^{i}} \right)} = {{\left( {M_{Lo2}^{i} - M_{{Lo}\; 2}^{f}} \right)*\rho} = {\Delta\; M*{\rho\left( M_{Lo2}^{i} \right)}}}}} & {{Equation}\mspace{14mu}{{\# 1}.}}\end{matrix}$

Therefore, the change in mass at a given point in time can indirectlyreflect the amount of ALA lost into solution by the simple applicationof the concentration value (p) times the mass lost (AM).

A determination of the ALA placed in solution over a given unit time isby definition a release rate calculation. Thus, if the change in mass isknown, and the time interval is known, it is possible to indirectlydetermine the release rate by the following formula: {(masschange)x[ALA]}/(time interval).

In this process artificial saliva as specified above is used for thedissolution medium. Although this artificial saliva must be kept at 35degrees C., as in the Determination of Optimal Dissolution ConditionsProtocol listed below, the use of a specific apparatus is not required.

A single lozenge is placed within a containment vessel filled with 100mL of artificial saliva (35 degrees C.) after its initial mass isdetermined. The lozenge is then removed at 2-minute intervals with apair of clean dry forceps, gently blotted dry with a Kimwipe™, andweighed again. This process is continued until the lozenge is too smallto accurately handle and/or weigh. A graph of the resulting data canthen be used for release rate analysis. The slope of the graph reflectsthis indirectly determined release rate at any given point during theexperiment.

An example of this process is listed below with the data produced from asingle in situ oral dissolution trial utilized to provide clarity. Theactual dissolution procedure listed in this section is expected to beslightly longer due to differences in temperature and the absence ofenzymic factors, thus sampling at one-minute intervals is expected toreflect conditions acquired during the ex-vivo procedure when samplingat two-minute intervals.

TABLE 5 Repeated In situ Oral Dissolution Trial Results (3.43 g Avg, 3%ALA, hard candy sugar lozenge) Change mg mg Release Time Weight Weight %ALA ALA in Rate (min) (g) (g) ALA Lost Solution (mg/min) 0 3.43 0 3 00.00 0.00 1 3.43 0.59 3 17.63 17.63 17.63 2 2.84 0.67 3 20.18 37.8020.18 3 2.17 0.55 3 16.58 54.38 16.58 4 1.62 0.49 3 14.70 69.08 14.70 51.13 0.46 3 13.65 82.73 13.65 6 0.67 0.32 3 9.53 92.25 9.53 7 0.36 0.213 6.15 98.40 6.15 8 0.15 0.10 3 3.08 101.48 3.08 9 0.05 0.05 3 1.43102.90 1.43

The use of one-minute intervals may introduce spurious data in thecollection process due to repeated exposure to air, mechanical friction,and the lozenge surface softening (partial dissolution) occurring withsaliva remaining on the lozenge surface while it is outside the cavityduring the weighing process (about 30 seconds). Additional two-minuteand four-minute sampling should be performed to provide context thatinforms how the issue of weighing the dissolving lozenge every minuteimpacts the dissolution rate.

It is clear that it is possible to create an indirect analysis of therelease rate of thioctic acid from a dissolution procedure that matchesexpected molecular kinetic models. This indirect method, althoughlacking modern sophistication and elegance, provides a simple, costeffective, statistically significant, and reasonably meaningful means ofcomparing various formulations, but would be expected to lack theconsistency of the ex vivo methods and/or have less standard deviation.

This mass loss method to determine thioctic acid release, applied toin-vivo dissolution trials as performed in this trial, can be used toprovide direct insight into factors affecting individual subjects duringthe actual use of lingual thioctic acid lozenges. Various measurementsof saliva contents during in situ trails could provide insight intolevels of salivary mucin release, lipase and amylase release, and otherphysiological factors.

Those individuals who display abnormal dissolution rates during in situtrials could be singled out for more extensive investigation into themechanisms of oral absorption, providing insight into the molecularmechanisms of oral tissue and cellular level thioctic acid uptake andrelease.

B) Determination of Optimal Dissolution Conditions for Release RateAnalysis

The USPC Type 2 Paddle Dissolution Testing Apparatus is a standard inthe industry but recent reports have shown that this equipment setup canproduce erroneous data. For this reason, the Type 4 Flow-ThroughApparatus is preferred and also specified in this protocol.

In either instance, artificial saliva (described above) is kept at 35degrees C. (+/−0.5 degrees C.) and utilized as the dissociation medium.USPC Type 2 Apparatus

This type of apparatus utilizes a closed vessel and agitates the fluidwithin it during the dissolution process. The vessel is continuouslyfilled with released product such that the concentrations of theingredients to be examined rise during the dissolution procedure. Forthis reason, chemicals that have a low aqueous saturation level can failto dissolve into solution with a kinetics that matches in situconditions.

As specified by the 2011 United States Pharmacopeial Convention thistype of dissolution apparatus consists of a reaction vessel of inerttransparent material, a motor driven stirring element, and a heatingelement or water bath that maintains the temperature at its specifiedparameter.

The size of reaction vessel is critical to the data obtained, as is thepaddle rotation speed and temperature. The maximum size of the holdingvessel for this protocol should be 1 liter (although a smaller chamberwould be preferable). The temperature must be maintained at 35 degreesC. (+/−0.5 degrees C.), and an initial Paddle Speed of 50 RPM should beutilized.

A minimal paddle speed of 5 RPM can be utilized during the optimizationprocedure, and a maximum of 150 RPM. Values outside this range areexpected to produce erroneous data since there is less agitation insitu.

Examples of this type of equipment commercially available include, butare not limited to, the Distek 6100 Dissolution System, the Pion pDISSProfiler, and the Agilent Varian VK7025 Dissolution System Apparatus.

USPC Type 4 Apparatus

This type of apparatus utilizes a continuous flow of dissolution mediumto record the immediate release rate of a lozenge, such that localconcentrations are never able to build up beyond a limited level. Thisis expected to more closely mimic the conditions seen in situ. For thisreason, this apparatus setup is preferred.

As specified by the 2011 United States Pharmacopeial Convention thistype of dissolution apparatus consists of a reservoir and pump for thedissolution medium (artificial saliva), a water bath that maintains thedissolution medium at 35 degrees C. (+/−0.5 degrees C.), and a flowthrough cell.

The pump must maintain a constant flow (+/−5% flow rate) and have a flowprofile that is sinusoidal with a pulsation of 120+/−10 pulses perminute (although a pump without pulsation may be used). The rate andpulsation parameters must be consistent and recorded for any analysis tobe valid and comparable.

Initial conditions should be such that a flow rate of 6.0 mL/min is setand maintained prior to the introduction of the lozenge into the testchamber. During testing of the Optimal Dissolution Conditions this flowrate is expected to be adjusted between runs until the flow rate thatproduces a dissolution time equivalent to that seen in situ is produced.The upper maximum for the ideal flow rate should not exceed 15 mL/min,since this condition far exceeds the rate at which saliva is introducedand removed from the buccal cavity.

The transparent and inert flow-through cell is mounted vertically in awater bath with a filter system that prevents the escape of undissolvedparticles from the top of the cell and has a standard size of 12 or 22.6mm. The bottom cone is filled with glass beads of 1-mm diameter, withone 5 mm bead positioned at the apex to protect the fluid entry tubefrom debris. The size of the filter screening system utilized must berecorded and validated for any analysis to be valid and comparable sinceit can vary from dissolution apparatus to dissolution apparatus.

Example of this type of equipment commercially available include, butare not limited to, the Erweka Flow Through Cell DFZ 720 Open and ClosedOffline system, and the Sotax CE 7Smart Semi-Automated UV-VisOn/Off-Line Closed Loop.

Optimization Procedure

Since the goal of this protocol is to find the optimal conditions underwhich ex vivo dissolution occurs, at this point the use of a dissolutionapparatus does not entail the collection of eluted fractions.

For the Type 2 apparatus the dissolution procedure is repeated,adjusting the Paddle RPM on each trial until an in situ comparable rateof dissolution is obtained. This optimal paddle speed will be utilizedduring release rate analysis using the same equipment setup.

For the Type 4 apparatus the dissolution procedure is repeated,adjusting the flow rate on each trial until an in situ comparable rateof dissolution is obtained. This optimal flow rate will be utilizedduring release rate analysis using the same equipment setup.

Specific Details of the AlphaBon™ Lozenge Release Rate TestingProtocol(s)

TABLE 6 Solvent for AlphaBon ™ Dissolution Rate and Thioctic AcidRelease Rate Testing: Artificial Saliva KH₂PO₄  2.5 mMol/L(Monopotassium Phosphate) Na₂PO₄  2.4 mMol/L (Disodium Phosphate) KHCO₃15.0 mMol/L (Potassium Bicarbonate) NaCl 10.0 mMol/L (Sodium Chloride)MgCl₂  1.5 mMol/L (Magnesium Chloride) CaCl₂  1.5 mMol/L (CalciumChloride) Citric Acid 0.15 mMol/L (Distilled water to volume)

For either the Type 2 Paddle Dissolution Apparatus or the Type 4Flow-Through Dissolution Apparatus, the dissolution medium is theArtificial Saliva listed above (in Table 6), kept at 35 degrees C.(+/−0.5 degrees C.). For the Type 2 Apparatus, the paddle speed is setto that value determined to be optimal during the dissolutionoptimization procedure. For the Type 4 flow-through Apparatus the flowrate is set to that value determined to be optimal during thedissolution optimization procedure.

For the Type 2 Paddle Apparatus, 50 μL samples are drawn out of thereaction at 10-20 (ideally 10) specified time points, either viaautomation or manually. For those samples to be analyzed via automationthe system is allowed to determine the concentration of Thioctic acid ineach fraction via UV (or other detection methods). For manual analysis,each fraction is to be stored in separate aliquots, frozen, and utilizedfor later thioctic acid concentration analysis via the appropriatedetection methodology.

For the Type 2 Flow-Through Apparatus 10-20 (ideally 10) separate 20 μLeluent samples are either immediately analyzed by the system or storedin separate aliquots, frozen, and utilized later for thioctic acidconcentration analysis.

The data produced from the Type 2 Apparatus will reflect an increasingconcentration of thioctic acid in solution, while the data obtained fromthe Type 4 Apparatus will reflect how much is being released within asmaller unit of time. Both types of analysis are scientifically soundand have a higher validity than the mathematical dissolution model notedabove for use during in situ investigations.

Specific Details of the HPLC/Electrochemical Thioctic Acid ConcentrationDetermination Protocol

The samples obtained from the USPC Type 2 or USPC Type 4 apparatus areinjected into the HPLC, which utilizes a mobile phase buffer that is 50%Acetonitrile in 0.05 M Potassium Dihydrogen Phosphate, adjusted to a pHof 2.5 with Phosphoric acid. The HPLC itself utilizes Nucleosil 120-C185 μm columns, with a flow rate set at 1.0 mL per minute, and a guardcolumn. An electrochemical detector equipped with a glassy carbonelectrode set at a potential of +/−1.1 V should be used to quantify theresults.

For this protocol, calibration controls will be linear within the 100 ngto 5 μg range, and so 257 ng concentrations of lipoic acid inacetonitrile should be used for each daily run. These calibrationstandards MUST be freshly prepared at the beginning of each HPLCanalysis run.

The height of each lipoic peak is measured and recorded for each timepoint. The height of calibration controls for each daily run are thenaveraged, and ng per mm values obtained from these averages. Thesevalues are then used to compute lipoic acid concentrations in plasma foreach time point. Data is subsequently adjusted to normalize anyvariations in dosages and to reflect dilutional effects (i.e.,multiplied by two).

For each formulation, the maximum peak is determined, and the totalabsorbed lipoic acid is estimated from an area under the concentrationtime curve (AUC) analysis of the kinetic curves. For the most part, noconsideration should be given to racemic compositions and differences.

20 μL HPLC Sample Analysis

Turn on ECD and HPLC and allow system to equilibrate.

Inject 2.0 μg/mL standard and allow system to fully return to baseline.

Repeat 2.0 μg/mL standard injection (checks that HPLC system is stable).

Inject Sample and allow system to return to baseline.

(repeat steps 3 & 4 for each sample to be analyzed).

Inject 2.0 μg/mL standard and allow system to fully return to baseline.

Average the areas (or heights) for the standard and divide by 2.0 toproduce an area per pg (or mm per μg) value.

Divide the sample's reported area (or height) by the value produced instep (6) above to compute the sample's actual lipoic value in μg/mL.

HPLC Testing Specifics a) HPLC System Preparation

Make sure that the HPLC has no leaks, and that both in-line filters andguard columns are fresh enough to allow a good flow. To be sure this isso, check the PSI on the pump, which should be about 2.5 K at the startof a run (before samples clog the system).

If the system has not been used for several days, it should be runningnon-buffered mobile phase. Therefore, shutting down the pumpmomentarily, switch the Mobile phase on line (A) from a Non-BufferedMobile Phase bottle to a Buffered Mobile Phase bottle.

If the system has been used within the last day, it should already berunning buffered mobile phase.

Ideally, the ECD and HPLC should be switched to Buffered mobile phaseand allowed to run at 0.3 mL/min overnight prior to actual use.

Either way, the HPLC should run Buffered Mobile phase for at least threehours prior to actually performing sample injections and be set to aflow rate of 1.0 mL/min prior to and during injections.

b) ECD System Preparation

Polish the cell contacts within the top cabinet of the ECD.

Replace the reference electrode with a re-charged one that has beenstored in a high concentration of NaCI for at least three days.

With the ECD set to standby, turn the system to an AppE of 1.001, arange of 1.0, and a filter of 0.10 or 0.15.

Ideally, the ECD and HPLC should be switched to Buffered mobile phaseand allowed to run at 0.3 mL/min overnight prior to actual use. If thisis not possible, at least three hours must pass if solvent is changed ordetector components have been altered.

In either case, let the system run at the flow rate used for injections(1.0 mL/min) for 15-20 minutes before using it, especially if the flowrate or sensitivity range has been changed (either right before, orduring sample injections).

If the detector must be re-set (i.e., with a new reference electrodeand/or cell polishing), at least three hours must pass before subsequentuse.

c) HPLC Sample Injection Procedures

With the HPLC and ECD at full equilibrium (see above), 50 μL are drawnwith a calibrated syringe from that day's 260 ng standard, and about 40μL are injected into the manual injector while it is the “LOAD” position(DO NOT TRY TO DELIVER ALL 50 ul's, since this can introduce an airbubble into the system). Given that the system uses a 20 μL loop, thissize sample ensures uniform loading and clearing of trace amounts fromthe needle injector port).

Turn the Manual Injector to “Inject” and hit the Marker switch on thefront of the ECD.

This ensures that a dash is created on the chart, so that it is possibleto determine which of the following peaks is actually that belonging tothe ALA in the sample.

Flush the syringe itself 4-6 times with pure acetonitrile to removeexcess ALA and other debris.

When the chart moves far enough to make it possible to connect a line tothe hash mark, record on the chart what has been injected and enclose itin a rectangular box.

At a specific time, from 5-8 minutes post injection (depending upon thePSI, room temperature, and other factors), the ALA peak with show up onthe chart. Label that peak with a note enclosed in a balloon shaped box(in this case, as the 260 ng standard).

Once the ALA peak has passed and the chart is at baseline again, resetthe injector to “Load” and repeat the above procedure with a second 260ng standard.

Following the initial two injections of 260 ng standards, sampleinjections can begin.

Samples should be injected as per the standards, but in a random tandemorder. In other words, all samples for a given time point should beprocessed together, but the time points themselves should be randomized(see example below).

The syringe should be well cleaned between every injection, and a giventime point series should be followed by a single 260 ng standardinjection (see example below) to test ECD integrity and ensuresensitivity decline is accounted for during analysis.

In the event that detector sensitivity declines too greatly, the systemshould be shut down and the cause of the problem addressed beforefurther sampling is done. In the event of this occurrence, all remainingsamples should be quickly returned to the freezer for subsequent use.

d) HPLC System Shut Down Procedures

Unless the HPLC's PSI is still low, the inline filters should be changedat the end of a day's sample runs. Before doing this, remember to putthe ECD in standby and shut down the pump.

Following filter (and perhaps guard column) changing, the HPLC should beturned back on and allowed to clean itself out for at least 15 minutesat 1.0 mL/min.

If the ECD has lost sensitivity, replace reference electrode and polishcell (see above) before turning HPLC back on.

If the system is to be used within the next 24 hours, keep bufferedmobile phase running, but turn flow rate down to 0.3 mL/min.

If the system is NOT to be used for several days, then switch tonon-buffered mobile phase and let it run through the system for at least15-30 minutes at a 1.0 mL/min flow rate before switching to 0.3 mL/minflow rate.

Once the system is running “clean”, place outlet line into inlet bottle(so fluid returns to the same bottle it is leaving).

Ideally, a separate bottle buffered mobile phase should be used forovernight re-circulation than that used for actual HPLC analysis, inorder to minimize the chances of contamination. In this case, one bottleof buffered mobile phase would be used during the HPLC, while anotherwould be used to keep the system ready for use. Thus, the non-bufferedmobile phase should only be used if the system is going to be put instandby, for use several days later.

HPLC Data Analysis a) ALA Manual Peak Height Measurement

Using a straight edge, draw a line that connects the two ends of thebaseline below the given peak.

Using the caliper set in mm (not inches) and being sure to re-zero thegauge before each measurement, measure the distance from the drawnbaseline to the top of the peak and record it next to the label for thatpeak.

Note: If a given peak goes off the chart, that sample should be re-runat a higher range (e.g., 5.0 or 10.0 rather than 1.0).

b) ALA mm to ng/mL Conversions

Using the 260 ng standards as true values, take the average of two ormore values and divide that average by 260. This will give you the mm/ngvalue for any given peak's mm height.

Under the conditions outlined above, there will be two 260 ng values atthe start of the run, and then one immediately after the first round ofsamples. These samples would utilize this mm/ng factor to determine howmuch ALA is present. The STD error for these sample points is the STDerror in this first average.

Subsequent samples will be bracketed by two 260 ng standards. Thesestandards are averaged with the previous average, and again the STD inthis new average is assumed to be the STD in the samples that use thisnew average to compute mm/ng values.

HPLC Liquids and Standards Preparation Protocols a) Buffered MobilePhase Recipe (Makes 2.0 Liters)

Label a clean 2.0-liter bottle “BUFFERED MOBILE PHASE—50% ACN”.

Using a clean flask, add 1.0 liter of pure, distilled water.

Measure out 13.610 grams of Na₂HPO₃ (Disodium Phosphate), recordingactual mass, and add to the 1.0 liter of water.

Add phosphoric acid dropwise until pH is about 3.0, testing after everyfew drops.

Add 1.0 liter of HPLC grade acetonitrile to the 1.0 liter of pH balancedbuffer.

Filter the resulting 2.0 liters of mobile phase to remove excess saltand micro-particles.

Pour the filtered mobile phase into the labeled bottle and seal.

Record the date, and who made the mobile phase, on the side of thebottle and leave for HPLC technician.

sb) Non-Buffered Mobile Phase Recipe (Makes 2.0 Liters)

Label a clean 2.0-liter bottle “RECIRCULATE MOBILE PHASE—50% ACN”.

Using a clean flask, add 1.0 liter of pure, distilled water.

Add 1.0 liter of HPLC grade acetonitrile to the 1.0 liter of pure water.

Filter the resulting 2.0 liters of mobile phase to removemicro-particles.

Pour the filtered mobile phase into the labeled bottle and seal.

Record the date and who made the mobile phase on the side of the bottleand leave for HPLC technician.

c) Creation of 2.6 μg ALA Calibration Standard Solution

Place 200 mg of ALA in 30 ml Acetonitrile (this solution is 6.6 mg/mL).

Using a clean stir bar, mix until fully dissolved.

Place 24.5 mL of pure Acetonitrile in a large centrifuge tube.

Add 0.5 mL of 6.6 mg/mL ALA stock solution and mix (this solution is0.132 mg/mL ALA).

Place 24.5 mL of pure Acetonitrile in another centrifuge tube.

Add 0.5 mL of 0.13 mg/mL ALA solution and mix (this solution is 2.64μg/mL ALA, and is the standard from which 20 μL samples are drawn).

d) 260 ng ALA Sample Standard Preparation

Get 1 small (5.0 mL), and three large (50.0), fresh centrifuge tubes(with caps).

Write the date on each tube.

Label the small (5.0 mL) tube “Stock—0.033 g/mL ALA”.

Place 4.0 mL of acetonitrile into this tube.

Weigh out 0.133 grams of ALA, recording actual mass, and add to theacetonitrile containing tube.

Cap and mix this solution until it becomes homogeneous.

Label one of the large (50 mL) centrifuge tubes “1-1.0 mg/mL ALA”.

Add 49.0 mL of acetonitrile to this tube.

Remove 1.0 mL of liquid from the first tube (0.033 g/mL) and add to this49.0 mL of acetonitrile.

Cap both tubes and mix the second tube for several minutes.

Label a second large (50 mL) centrifuge tube “240 ug/mL ALA”.

Add 49.5 mL of acetonitrile to this second tube.

Remove 0.5 mL of liquid from the tube labeled “1-1.0 mg/mL ALA” and addto this 49.5 mL of acetonitrile.

Cap both tubes and mix the new tube for several minutes.

Set aside the “14.0 mg/mL ALA” tube.

Label the third large (50 mL) centrifuge tube “3-260 ng/mL ALA”.

Add 48.7 mL of acetonitrile to this large tube.

Remove 1.3 mL of liquid from the “240 ug/mL ALA” tube and add to this48.7 mL of acetonitrile.

Cap both tubes and mix the new tube for several minutes.

Set aside the “240 ug/mL ALA” tube.

The new tube, “3-260 ng/mL ALA” is the standard that is utilized on thatgiven day.

The original tube, “Stock—0.033 g/mL”, can be used for standard creationon other days within 1 week of its creation, but all the other tubes(1-3) are only good for the day they are made and should be discarded atthe end of the day.

Conclusion

When the diffusion-limiting binding agent is used as alingual/sublingual delivery system, it provides a uniquely andsynergistically effective method of delivering thioctic acid to apatient's bloodstream in supplemental and therapeutic doses.

1. A method of screening patients to select a dissolvable alpha-lipoicacid tablet composition made without heating the ingredients of thetablet formulation to a temperature at which any ingredient of thetablet composition melts, for treating a disease or condition treatableby an increased concentration of alpha-lipoic acid in the circulation,the method comprising: a. administering to a patient a first orallydissolvable tablet composition, the tablet composition being an orallydissolvable sustained release formulation comprising alpha-lipoic acidwherein the alpha-lipoic acid release comprises a first and a secondpeak release rate; b. directing the patient to fully dissolve the firsttablet composition in the patient's mouth; c. evaluating the patient'stolerance to said first tablet composition; d. administering to the samepatient one or more additional sustained release, orally dissolvabletablet compositions containing a different amount of alpha-lipoic acidthan that in the first tablet composition, a different release limitingformulation than that of the first tablet composition, or both, eachadditional tablet composition administered to the patient one tablet ata time and separate from any other tablet composition; e. directing thepatient to fully dissolve each additional tablet composition in theirmouth, one at a time; f. evaluating the patient's tolerance to eachadditional tablet composition; and g. prescribing to the patient acourse of treatment comprising administering one or more types of orallydissolvable, sustained release, tablet compositions comprising a firstand a second peak release rate based upon the patient's disease orcondition and the patient's response to the first tablet composition andthe one or more additional tablet compositions.
 2. The method of claim1, wherein the rate of release of alpha lipoic acid from the one or moretablet compositions administered after the first tablet compositiondiffers from the release rate of alpha-lipoic acid from the first tabletcomposition and comprises a first and a second peak release rate ofalpha-lipoic acid.
 3. The method of claim 1, wherein the concentrationof alpha-lipoic acid in the one or more tablet compositions administeredafter the first tablet composition differs from the concentration ofalpha-lipoic acid in the first tablet composition.
 4. The method ofclaim 1, wherein both the rate of release of alpha lipoic acid from, andthe concentration of alpha-lipoic acid in, the one or more tabletcompositions administered after the first tablet composition differsfrom the rate of release of alpha-lipoic acid from, and theconcentration of alpha lipoic acid in, the first tablet composition,wherein the sustained release of alpha-lipoic acid from each tabletcomposition administered after the first tablet composition comprises afirst and a second peak release rate.
 5. The method of claim 1, whereinthe prescribed course of treatment comprises at least one tabletcomposition comprising alpha-lipoic acid having the highestconcentration of alpha-lipoic acid that the patient can tolerate, thefastest release rate of alpha-lipoic acid that the patient can tolerate,or both the highest concentration of alpha-lipoic acid and the fastestrelease rate of alpha-lipoic acid that the patient can tolerate, basedon the level of burning sensation experienced by the patient at a givenalpha-lipoic acid concentration, alpha-lipoic acid release rate, orcombination of alpha-lipoic acid concentration and release rate.
 6. Themethod of claim 1, wherein the method comprises considering the pain ordiscomfort experienced by a patient due to a disease or conditiontreatable by alpha-lipoic acid administration and providing patientsexperiencing greater levels of disease-related or condition-related painor discomfort than the disease-related or condition-related pain ordiscomfort experienced by another patient one or more tabletcompositions comprising a higher concentration of alpha-lipoic acid, afaster release rate of alpha-lipoic acid, or both a higher concentrationand a faster release rate of alpha-lipoic acid than that of tabletcompositions provided to patients experiencing lower levels ofdisease-related or condition-related pain or discomfort.
 7. The methodof claim 6, wherein the disease or condition is selected from a groupcomprising general nutritional deficiency, Alzheimer's disease, diabeticneuropathy, and retinal neuropathies.
 8. The method of claim 7, whereinthe disease or condition is diabetic peripheral neuropathy.
 9. A methodof increasing the concentration of alpha-lipoic acid in an individualcomprising (a) delivering a dissolvable, compressed tablet, made withoutthe application of heat to a temperature at which any ingredient in thecompressed tablet melts, comprising alpha-lipoic acid in a concentrationof 7.5-27%, to the mouth of the individual such that dissolving thedissolvable, compressed tablet in the mouth results in a variablesustained release profile comprising a first and a second peak releaserate of alpha-lipoic acid from the dissolvable, compressed tablet, and(b) maintaining the compressed tablet in the mouth of the individualuntil the compressed tablet is fully dissolved without the individualexperiencing a burning sensation which causes the individual to beunable to maintain the compressed tablet in their mouth until thecompressed tablet is fully dissolved.
 10. The method of claim 9, whereinthe alpha-lipoic acid is racemic ALA.
 11. The method of claim 9, whereinadministration of the compressed tablet results in the bloodconcentration of alpha-lipoic acid in the individual reaching at least65% of the concentration achieved by intravenous administration of thesame amount of alpha-lipoic acid.
 12. The method of claim 9, wherein thealpha-lipoic acid in the compressed tablet is in a concentration of9-27%, and the average response in a population of at least 12 testsubjects is that the compressed tablet is acceptable for daily usedespite any irritation incurred in fully dissolving the tablet in themouth.
 13. The method of claim 12, wherein administration of thecompressed tablet results in the blood concentration of alpha-lipoicacid in the individual reaching at least 65% of the concentrationachieved by intravenous administration of the same amount ofalpha-lipoic acid.
 14. The method of claim 10, wherein the alpha-lipoicacid in the compressed tablet is in a concentration of 9-27%, and theaverage response in a population of at least 12 test subjects is thatthe compressed tablet is acceptable for daily use despite any irritationincurred in dissolving the tablet in the mouth.
 15. The method of claim10, wherein administration of the compressed tablet results in the bloodconcentration of alpha-lipoic acid in the individual reaching at least65% of the concentration achieved by intravenous administration of thesame amount of alpha-lipoic acid.
 16. The method of claim 13, whereinadministration of the compressed tablet results in the bloodconcentration of alpha-lipoic acid in the individual reaching at least85% of the concentration achieved by intravenous administration of thesame amount of alpha-lipoic acid.
 17. The method of claim 11, whereinadministration of the compressed tablet results in the bloodconcentration of alpha-lipoic acid in the individual reaching at least85% of the concentration achieved by intravenous administration of thesame amount of alpha-lipoic acid.
 18. The method of claim 15, whereinadministration of the compressed tablet results in the bloodconcentration of alpha-lipoic acid in the individual reaching at least85% of the concentration achieved by intravenous administration of thesame amount of alpha-lipoic acid.